good evening, rachel maddow. >> thank you for staying with us. we're going to have the latest on the aftermath and the continuing news out of newtown connecticut tonight as well as some other important politics, news that is not related to what happened in newtown. the brand new snat tor elect is chris murphy. the mayor of newark, new jersey is going to be joining us in just a moment. as is the police chief from oak creek wisconsin where that mass shooting occurred this past august. that is all coming up this hour. but, in order to understand one important element of the response to newtown, in order to try to get a handle on the range of possible outcomes here, as we try to make decisions as a country as to whether we are going to change as a country because of this massacre and because of the national heartbreak it has caused, to try to get at that very big question, there is a very narrow discussion to be had about a piece of new technology. this is something called a 3d printer. anybody can become a small-scale manufacturer of anything. all y